I just finished a course of making a mobile game, but when I save it as a phone APK file, this page opens.
Probably some project setting (edit-project settings), first make sure android is supported platform, make sure the project is configured for Android in project settings, make sure (android codeworks is set up for unreal (google how to do that), make sure the ARMV7 or other options in project settings is correct, if that doesn’t work youtube Unreal Android Project settings (or setup).
FYI with new settings and changes its possible that you will decide to start as a new project. Its easy to move your whole level, or character or pieces to new projects (if starting a fresh with proper settings turns out to be easier). Right click on the level or asset to migrate and hit migrate, then find the new project in the pop up screen and go inside the content folder of the new project and migrate the assets there.
Send a PM if you need more help (just be aware I dont always see messages right away)